A DFT study on the mechanisms of three-component reaction between imidazoles, isocyanates and cyanophenylacetylene

Li, Shi-Jun; Wei, Donghui; Zhu, Yanyan; Tang, Mingsheng

doi:10.1016/j.comptc.2013.05.021

Cited by 6 publications

(7 citation statements)

References 48 publications

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“…Polymerization Mechanism. To study the polymerization mechanism, we referred to the literature 58,61 studying small molecule reactions and proposed a tentative polymerization process of this MCP method, as shown in Scheme 2. During the initial stage, zwitterion I is necessary for this MCP process to occur and was derived from the initial nucleophilic addition of imidazole to acetylenic ester 1.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

“…To study the polymerization mechanism, we referred to the literature , studying small molecule reactions and proposed a tentative polymerization process of this MCP method, as shown in Scheme . During the initial stage, zwitterion I is necessary for this MCP process to occur and was derived from the initial nucleophilic addition of imidazole to acetylenic ester 1 . − Therefore, the concentration of the monomers is a very impactor factor for achieving thorough polymerization, which provides a sufficient amount of zwitterion I.…”

Section: Resultsmentioning

confidence: 99%

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Spontaneous Multicomponent Polymerization of Imidazole, Diacetylenic Esters, and Diisocyanates for the Preparation of Poly(β-aminoacrylate)s with Cluster-Induced Emission Characteristics

Dong

Liu

et al. 2020

Macromolecules

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Multicomponent polymerization (MCP) is an efficient and rapid method for obtaining multifunctional polymeric materials that have been widely developed in recent years. In this work, poly(β-aminoacrylate)s were obtained by spontaneous MCP with the assistance of the C2-amidation of 1-methylimidazole together with diacetylenic esters and diisocyanates. This process can be carried out under mild conditions, such as in a catalyst-free and room-temperature environment. Through the systematic optimization of the polymerization conditions, the resultant poly(β-aminoacrylate)s could have molecular weights of up to 24 100 g/mol and excellent yields (up to 94%). All the polymers were well-characterized by gel permeation chromatography (GPC), nuclear magnetic resonance (NMR), and Fourier transform infrared spectroscopy (FT-IR), and all the collected data illustrated that the polymerization mechanism corresponds to a model reaction of small molecules. The photophysical property of these obtained polymers indicated that one of the polymers (polymer P1b2a) demonstrated a luminescence capability that was unconventional because no fluorescent emitters were present in its main chains or side chains. A further study suggested that the clustering of diverse subgroups with subsequent electron cloud overlapping, which resulted in molecular conformation rigidification, was primarily responsible for this emission. Thus, the current MCP method will provide guidance for preparing new nonconjugated polymers with cluster-induced emissive functional materials for easily tailored specific applications.

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Section: ■ Results and Discussionmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Spontaneous Multicomponent Polymerization of Imidazole, Diacetylenic Esters, and Diisocyanates for the Preparation of Poly(β-aminoacrylate)s with Cluster-Induced Emission Characteristics

Dong

Liu

et al. 2020

Macromolecules

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“…As shown in Scheme , the [4 + 2] cycloaddition of enal ( R1 ) with α‐methylene cycloalkanone ( R2 ) catalyzed by NHC to form the tricyclic benzopyran‐2‐one ( P ) has been selected as the research object. In this work, we perform the density functional theory (DFT) calculation to all stationary points and study the detailed mechanisms of organic reactions …”

Section: Introductionmentioning

confidence: 99%

A density functional theory study on mechanisms of [4 + 2] annulation of enal with α‐methylene cycloalkanone catalyzed by N‐heterocyclic carbene

Zhu

et al. 2019

Int J of Quantum Chemistry

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Density functional theory was used to study the reaction mechanisms of the N‐heterocyclic carbene (NHC)‐catalyzed [4 + 2] annulation reaction between enal and α‐methylene cycloalkanone for the formation of tricyclic benzopyran‐2‐one. The simulations suggest that the energy‐favorable catalytic cycle includes five steps: (a) the nucleophilic addition of enal by NHC catalyst; (b) [1, 2]‐proton transfer for the formation of Breslow intermediate; (c) [1, 4]‐proton transfer for the formation of enolate intermediate; (d) the [4 + 2] cycloaddition process, product formation; and (e) catalyst regeneration. The proton transfer process was particularly designed in two independent ways, the direct proton transfer and the Brønsted acid DBU∙H+‐mediated proton transfer. Our study reveals that [1, 2]‐proton transfer process is the rate‐determining step with the accessible energy barrier, which agrees with the experimental observation. Further analysis of the global reaction index confirmed that NHC was primary used as a Lewis base during the reaction processes. The frontier molecular orbital (FMO) analysis indicates that the introduction of the NHC catalyst facilitates the reaction to occur due to the narrower energy gap of FMO.

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“…Density functional theory (DFT) (Da Costa et al, 2012;Li et al, 2013) is one of the most popular quantum chemistry theories, because DFT can provide a basis for the practical application at varying degrees. Espinal et al (2007) presented the mechanisms of NH 3 evolution during the reaction of hydrogen with nitrogen-containing carbonaceous materials via pyridinic nitrogen species as a model based on the density functional theory.…”

Section: Introductionmentioning

confidence: 99%

Mechanisms Study of NH₃Formation in the Reaction Between H₂and Char Edge Models Containing 2-Pyridone

Jing

Sun

Zhu

et al. 2014

Combustion Science and Technology

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Molecular modeling research based on transition state theory and density functional theory was performed to clarify the mechanisms for NH 3 evolution during the reaction of H 2 with char edge models containing 2-pyridone in zigzag and armchair configurations. The thermal chemical activation energy and enthalpy change were calculated in the overall process of NH 3 formation. The results indicate that formation of −NH 2 radicals is possible for both char edge models containing 2-pyridone in the zigzag and armchair configurations. Then, NH 3 can be produced through homogeneous hydrogen abstraction. It is found that the reaction of releasing NH 3 can be completed relatively easily with the char edge model containing 2-pyridone in the armchair configuration. Most pathways for NH 3 evolution appear to involve endothermic reactions for both configurations. These results provide a reference and basis for controlling the emission of nitrogen oxide.

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A DFT study on the mechanisms of three-component reaction between imidazoles, isocyanates and cyanophenylacetylene

Cited by 6 publications

References 48 publications

Spontaneous Multicomponent Polymerization of Imidazole, Diacetylenic Esters, and Diisocyanates for the Preparation of Poly(β-aminoacrylate)s with Cluster-Induced Emission Characteristics

Spontaneous Multicomponent Polymerization of Imidazole, Diacetylenic Esters, and Diisocyanates for the Preparation of Poly(β-aminoacrylate)s with Cluster-Induced Emission Characteristics

A density functional theory study on mechanisms of [4 + 2] annulation of enal with α‐methylene cycloalkanone catalyzed by N‐heterocyclic carbene

Mechanisms Study of NH₃Formation in the Reaction Between H₂and Char Edge Models Containing 2-Pyridone

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A DFT study on the mechanisms of three-component reaction between imidazoles, isocyanates and cyanophenylacetylene

Cited by 6 publications

References 48 publications

Spontaneous Multicomponent Polymerization of Imidazole, Diacetylenic Esters, and Diisocyanates for the Preparation of Poly(β-aminoacrylate)s with Cluster-Induced Emission Characteristics

Spontaneous Multicomponent Polymerization of Imidazole, Diacetylenic Esters, and Diisocyanates for the Preparation of Poly(β-aminoacrylate)s with Cluster-Induced Emission Characteristics

A density functional theory study on mechanisms of [4 + 2] annulation of enal with α‐methylene cycloalkanone catalyzed by N‐heterocyclic carbene

Mechanisms Study of NH3Formation in the Reaction Between H2and Char Edge Models Containing 2-Pyridone

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Mechanisms Study of NH₃Formation in the Reaction Between H₂and Char Edge Models Containing 2-Pyridone